A backhaul system is a communication system that is used to communicate certain data from a cellular network, for example, back to the central system in a communications system. Various different backhaul systems are well known that are both wireless communication systems and wired communication systems. Most of the current wireless backhaul systems are point to point (P2P) systems that operate in the licensed FDD (frequency division multiplexed or a frequency division protocol) microwave bands from 6 GHz to 80 GHz. These systems use high gain parabolic dishes which must be manually pointed and also rely on the low sidelobe performance of the dish to reduce (but not eliminate) co-channel interference. Moreover, these products must be used where line-of-sight is available.
These existing backhaul systems do not provide self alignment and realignment of the antenna beams or any increase in effective link spectral efficiency by using interference cancellation. These existing systems also do not operate in a non-line-of sight propagation environment, are not able to double the spectral efficiency by using two polarizations in this environment and have reduced link reliability due to fading. These existing systems do not cancel radio interference to optimize signal to interference and noise ratio (SINR) and do not cancel interference from other self-generated co-channel interference. These existing systems also do not have multi-target beam-forming that enhances spectral efficiency and can provide exceptional data concentration in small amounts of spectrum.
Furthermore, given the shortage of spectrum for broadband wireless and the need to increase both link rate and network capacity, wireless carriers are migrating from a traditional macro-cellular network topology 10 to a micro-cellular and pico-cellular topologies 20 as shown in FIG. 1. That is, instead of using a few high-high powered base-stations to cover large areas, they supplement these with many outdoor micro-cells and pico-cells as shown in FIG. 1.
The base station capacity (measured in Mbps) has been increasing slowly as operators migrate from 2.5G and 3G technologies (HSDPA, HSPA, CDMA 2000, CDMA EVO, etc) to 4G technologies (WiMax and LTE). However, 4G technology increases spectral efficiency only 50% relative to the previous generation. Yet, 4G will not solve the 10-fold increase needed to maintain a macro-cell topology while increasing user capacity. Hence, emerging wireless architectures solve the throughput problem by increasing “capacity density” (measured in Mbps per km2), and not by increasing capacity alone.
Increasing capacity density 10-fold can be solved by a dense deployment of micro- and pico-cells. Although these cells have limited range (100 to 500 meters), they retain the capacity similar to macro-cells, for the LTE standard 15 Mbps in 10 MHz of bandwidth and 39 Mbps in 10 MHz of bandwidth with 3-sectored implementations. Thus, a macro-cell with a range of 1 km (urban propagation) and capacity density of 15 Mbps/km2, evolves into a micro-cellular topology featuring a capacity density of 135 Mbps/km2 using 9 micro-cells.
Thus, it is desirable to provide a non-line of sight backhaul system and method that overcomes the above limitations of existing backhaul systems and it is to this end that the disclosure is directed.